1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2016 CNEX Labs
  4 * Initial release: Javier Gonzalez <javier@cnexlabs.com>
  5 *                  Matias Bjorling <matias@cnexlabs.com>
  6 *
  7 * This program is free software; you can redistribute it and/or
  8 * modify it under the terms of the GNU General Public License version
  9 * 2 as published by the Free Software Foundation.
 10 *
 11 * This program is distributed in the hope that it will be useful, but
 12 * WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 14 * General Public License for more details.
 15 *
 16 * pblk-cache.c - pblk's write cache
 17 */
 18
 19#include "pblk.h"
 20
 21void pblk_write_to_cache(struct pblk *pblk, struct bio *bio,
 22				unsigned long flags)
 23{
 24	struct pblk_w_ctx w_ctx;
 25	sector_t lba = pblk_get_lba(bio);
 26	unsigned long start_time;
 27	unsigned int bpos, pos;
 28	int nr_entries = pblk_get_secs(bio);
 29	int i, ret;
 30
 31	start_time = bio_start_io_acct(bio);
 32
 33	/* Update the write buffer head (mem) with the entries that we can
 34	 * write. The write in itself cannot fail, so there is no need to
 35	 * rollback from here on.
 36	 */
 37retry:
 38	ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
 39	switch (ret) {
 40	case NVM_IO_REQUEUE:
 41		io_schedule();
 42		goto retry;
 43	case NVM_IO_ERR:
 44		pblk_pipeline_stop(pblk);
 45		bio_io_error(bio);
 46		goto out;
 47	}
 48
 49	pblk_ppa_set_empty(&w_ctx.ppa);
 50	w_ctx.flags = flags;
 51	if (bio->bi_opf & REQ_PREFLUSH) {
 52		w_ctx.flags |= PBLK_FLUSH_ENTRY;
 53		pblk_write_kick(pblk);
 54	}
 55
 56	if (unlikely(!bio_has_data(bio)))
 57		goto out;
 58
 59	for (i = 0; i < nr_entries; i++) {
 60		void *data = bio_data(bio);
 61
 62		w_ctx.lba = lba + i;
 63
 64		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
 65		pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
 66
 67		bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
 68	}
 69
 70	atomic64_add(nr_entries, &pblk->user_wa);
 71
 72#ifdef CONFIG_NVM_PBLK_DEBUG
 73	atomic_long_add(nr_entries, &pblk->inflight_writes);
 74	atomic_long_add(nr_entries, &pblk->req_writes);
 75#endif
 76
 77	pblk_rl_inserted(&pblk->rl, nr_entries);
 78
 79out:
 80	bio_end_io_acct(bio, start_time);
 81	pblk_write_should_kick(pblk);
 82
 83	if (ret == NVM_IO_DONE)
 84		bio_endio(bio);
 85}
 86
 87/*
 88 * On GC the incoming lbas are not necessarily sequential. Also, some of the
 89 * lbas might not be valid entries, which are marked as empty by the GC thread
 90 */
 91int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 92{
 93	struct pblk_w_ctx w_ctx;
 94	unsigned int bpos, pos;
 95	void *data = gc_rq->data;
 96	int i, valid_entries;
 97
 98	/* Update the write buffer head (mem) with the entries that we can
 99	 * write. The write in itself cannot fail, so there is no need to
100	 * rollback from here on.
101	 */
102retry:
103	if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
104		io_schedule();
105		goto retry;
106	}
107
108	w_ctx.flags = PBLK_IOTYPE_GC;
109	pblk_ppa_set_empty(&w_ctx.ppa);
110
111	for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
112		if (gc_rq->lba_list[i] == ADDR_EMPTY)
113			continue;
114
115		w_ctx.lba = gc_rq->lba_list[i];
116
117		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
118		pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
119						gc_rq->paddr_list[i], pos);
120
121		data += PBLK_EXPOSED_PAGE_SIZE;
122		valid_entries++;
123	}
124
125	WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
126					"pblk: inconsistent GC write\n");
127
128	atomic64_add(valid_entries, &pblk->gc_wa);
129
130#ifdef CONFIG_NVM_PBLK_DEBUG
131	atomic_long_add(valid_entries, &pblk->inflight_writes);
132	atomic_long_add(valid_entries, &pblk->recov_gc_writes);
133#endif
134
135	pblk_write_should_kick(pblk);
136	return NVM_IO_OK;
137}